In order to accomplish audio editing, it is known to use a mixer to control a plurality of multi-channel devices, such as VTRs, for example. It is also known that an editor may be advantageously used to control the mixer via an editor interface to enable various VTR functions including PREVIEW/REVIEW and FADE UP/DOWN, for example. Accordingly, control signals can be sent from an editor to the mixer in order to preview audio signals at an edit-in point on a recording medium of a recorder VTR. Similarly, control signals may be sent from an editor in order to review audio signals output from a recorder VTR. In general, the PREVIEW/REVIEW functions require a digital signal (e.g. to be supplied to an appropriate channel) to activate the channel.
The FADE UP/DOWN functions generally require analog signals to be supplied to the appropriate channels. These signals are commonly referred to as VCA signals and are supplied to voltage controlled amplifiers associated with the channels. Other analog and digital control signals may be used to implement other known functions.
Generally, in a mixer system, a mixer is connected to a plurality of devices such as VTRs or other multi-channel devices, for example. The mixer may also be connected to an editor via an editor interface to enable editor control of the mixer. The editor interface may comprise either a parallel interface or a serial interface. Editor interfaces of the latter type offer several advantages. Primarily, however serial interfaces are advantageous in that they require fewer connections between the mixer and the editor.
Several drawbacks are found in prior art mixer systems used for audio editing. For example, prior systems generally enable editor control of either only all four-channel devices or only all two-channel devices. This is clearly an undesirable limitation. Some systems allow for the use of hard-wired jumpers to enable various combinations of two and four-channel devices to be used. This avoids the aforedescribed undesirable limitation, but adds a new drawback in that using hard wired jumpers is time consuming and can be difficult if several devices are to be connected. Additionally, if it is desired to reconfigure the devices, for example, to replace a four-channel device with 2 two-channel devices, rewiring is necessary, once again requiring a time consuming operation.
The system disclosed in U.S. Pat. No. 5,175,771 provides a solution to this drawback, offering a more convenient method to configure different combinations of two or four-channel VTRs without hard-wiring. This method utilizes a parallel interface between the editor and the audio mixer and a configuration selector to selected a desired configuration of a plurality of multichannel devices to enable the convenient mixing of such various configurations. One way of achieving such configuration selection is through the use of an output of the configuration selector provided to a memory to select prestored commands to be provided to appropriate channels. In another embodiment there disclosed, the configuration selection signals are decoded and supplied to multiplexers in combination with editor control signals through a parallel interface to enable the editor control signals to be routed to appropriate channels.
However, there remains a need to provide a method of controlling a mixing of audio channels input from a selected configuration of multichannel VTRs with an editor through a serial interface. There is a further need to incorporate into a mixer system the advantages of serial interfacing.